Grammatically, one should say:
more sincere than hypocrit ical.
more sincere than a hypocrite.
(but the first is better because the second is ambiguous).
Semantically, it is fine. It says that you are neither purely sincere nor purely hypocritical, but somewhere in between and leaning towards the sincerity side.
Pragmatically though, it is very strange. One would, in normal discourse, be considered either usually sincere or usually a hypocrite. And mentioning the other doesn't really add nuance. In fact it comes out as saying a very complex point, namely that people are different mixes of both sincerity and hypocrisy, every one with their own percentage of each or position along a scale. Most people don't consider themselves in any way hypocrites and wouldn't want to have others think of themselves in that way in the slightest. Knowingly honest (!) about the possiblity of being hypocritical just makes people think that you are hypocritical.
And frankly, claiming that one is sincere is like saying that 'I am not a crook'; it brings it into doubt (especially for 'sincerity'; how does one justify a statement like that, since it is about the truthfulness of ones words?).
And then remarking that there is the possibility of hypocrisy brings it much more into doubt.
The result of such a statement is that the listener wonders when exactly you are your hypocritical self, and so would distrust you most of the time (a listener would not take it to mean anything about them; they'd be wondering all about you).
As a result, yes, this is a fairly awkward statement to make of oneself. Though you might consider it an honest portrayal, it is a bit too honest. It is very similar to 'I tell the truth more often than not', which is very questionable to say (however accurate it might be).